Circuit breaker



T. A. SPERRY CIRCUIT BREAKER Jline 26, 1934.

Filed Dec. 25, 1931 2 Sheets-Sheet l Tzbam; 15,

Patented June 26, 1934 1 CIRCUIT BREAKER Theodore A. Sperry, Indianapolis, Ind., assignor,

' by mesne assignments, to Electric Devices Corporation, Indianapolis,-Ind., a corporation of Indiana Application December 23, 1931, Serial No. 582,716

20 Claims. (01. 200-416) My invention relates to electric circuit breakers vation of the switch contacts and arms, Figure 8 and switches in general, and has for primary being an isometric view of the main current carryobjects to provide a device which will function ing contact arm. Figure 9 is a plan view of a equally well either as a manually operated portion of trip adjusting mechanism, Figure 10 switch oras an automatic circuit breaker; to probeing a side elevation and a plan view of the 60 vide a circuit breaker in which the automatic linkage overarm, while Figure 11 is a side and a action is entirely independent of the manually front elevation of the upper toggle member. operating handle; to provide a circuit breaker in Figure 12 is a plan and a side view of the thermal which the main current carrying contacts will be element, Figure 13 being similar views of the opened before the current itself is broken; to manual operating handle, while Figure 14 i a 05 provide a switch mechanism that will close the detail of the tripping member. It is understood circuit with a quick and positive action before that these views are for illustrative purposes only the main current carrying'contacts will be closed; and do not limit the device to any definite detO Provide a eilellii'l breaker p e y and tails and combinations of construction which may 15 mechanically forces the Opening linkage to properly be claimedand construed under these 70 operative position when operated on overload specifications and laims, conditions; to provide a circuit breaker which With further reference to the drawings, in P v y forces the op g linkage toward inwhich like numerals refer to like parts throughp iv p t before th manual hand out, the numeral 15 indicates a base of insulating starts to -move; to provid a circuit breaker material, and acover 16 removably secured there- 75 havi an evel'eentelm Spring to p the circuit to as by a plurality of screws 17 andnuts 18, the and a pp nt y sp n wh h will autoscrews preferably being embedded in the base 15 matica y and independently Open t cu if so that it will be necessary to remove the device the main p a Spring beeemesihepeletivei from its mounting board before the cover can be t p v d a i u breaker in which he a removed from the base. An entrance electric 80 element is entire y embedded in the base Where it conductor 19 is provided with a depressed portion cannot b r nd d i p t t P v d 8 having inclined sides 21 to rigidly engage acarbon circuit breaker in whic the Operative Pressure contact 20, is securely mounted at one end of on the thermal element shall be am um 150 the base 15, and is provided with an inner contact insur accura y of op ati t p vid a cir uit surface 22. A U-shaped frame housing 23, hav- 85 breaker which shall have an independently opering a trip opening 24 in the bottom of the U, is at v duel Sy Of Operation; to provide 5 mounted on the base 15 in alignment with the eiliii breaker Particularly adaptable to Service conductor 19, and is provided with a through piventrance installations which will be small and otal shaft 25 which supports a swinging frame 26 comp an f l w m in n n an m n fa to which are fixedly attached a plurality of flexiturins cost, n in whi h a in le movem nt f ble spring leaves27, ashorter spring leaf 33 and e Switch handle Only s required to re-establish a current carrying member 34, the latter being the circuit after operation on overload conditions. preferably provided with a plurality of furcated Other j c will pp r as these p ifi i n fingers as each of which has a contact button 36 proceed. adjacent its outer extremity. Spring leaves 27 95 In the accompanying drawings, illustrating a carry a pair of loosely mounted rivets 28 adjacent Preferred form Ofthe device, Figure '1 is 9- Side their outer extremity to loosely support an elecelevation of the device, the cover portion being tric conducting housing 29 having inwardly 1 in section, Figure 2 being a similar elevation in clined side members 31 securely gripping acarbon section through the center line of the unit while in contact 30, a portion of the carbon being cut 100 inoperative position. Figure 3 is an essentially away, as at 32, to provide clearance for the lower similar l v tion sh wi h d vi e during its heads of the rlvets28. A helical spring 37 is operation under overload conditions, Figure 4 loosely positioned on the shaft 25 with one probeing a p Vi Of a duel unit with a Portion f jecting end 39 engaging the swinging frame 26 the cover, one of the units and a portion of the while its other end 38 engages a stop 40 formed other unit removed. Figure 5 is an end elevation integral. with the frame 23 the tension of this of a dual unit essentially on the broken line 5-5 spring 37 tending to elevate the spring leaves 27 of Figure 4, while Figure 6 is a diagrammatic and the carbon 30. elevation of the operative linkage in superimposed Pivotally secured to the swinging frame 26, as

positions: Figure 7 is an enlarged sectional eleat 91, is a pair of link plates 41 carrying a U-.-

shaped toggle link 42 having a lower extension 43 with an oifset cross bar 44 to which one end of the main operating helical spring 62 is secured. Link 42 is pivoted, as at 45, to plates 41, and carries a plurality of notched wings 46 adjacent its extremities. These notched wings loosely engage the side arms 49 of an upper frame 47, which is pivotally mounted, as at 48, to the housing 23. Frame 47 has a cross member 50 which projects forwardly, as at 51, and is cut away, as at 53, to provide clearance for the spring 62, an essentially right-angled shoulder 52 engaging the wing notches 46, and a trip engaging stud 54 being riveted in the outer ends of the arms 49. Pivotally secured on frame 23 in spaced relation to the pivot 48, as at 56, is a bifurcated manual operation handle 55 with spaced side bars 95 carrying a plurality of lateral wings 61 to engage the upper frame 47 after operation of the circuit breaker on overload conditions. Side bars 95 carry a fixedly secured pin 57 to which is attached one end of the main operating spring 62, and a knob 58 of insulating material is cementedly secured upon the outer convoluted portion of the handle 55, said knob having a plurality of lateral wings 59 to continually close the opening 60 in cover 16. The wings 61 also serve as a limit stop to the arcuate travel of handle 55 by engagement with a shoulder 90 on the frame 23.

An adjusting bracket 72 having a depending wing 74 carrying an arcuate slot 75 is pivotally secured, as at 73, to the frame 23 in spaced relation to pivots 25 and 48, a lock screw 76 being provided to maintain said bracket in adjusted position. A shaft 64, mounted in the bracket 72, supports a trip lever 63having a lateral wing 65 to maintain an arcuate alignment of said lever in relation to said shaft, said lever having a depending leg 66 terminating in a strike 67, andan upward projecting arm 68 carrying a formed slot 69 which terminates with an abrupt oifset portion 70 adjacent the shaft 64, forming a definite heel 71 for engagement of the pin 54 which is carried by the frame-47. The strike 67 normally engages a projection 87 formed on a clip 86 which is secured upon and essentially surrounds the middle portion 96 of a U-shaped bimetallic thermal element 79, said clip being insulated, as by an insulating sheet 88, from the element 79, but maintained thereon by a plurality of forced indentations .89 in addition to its surrounding grip. A recess 77 with a separating tongue 78 is formed within the base 15 to surround the thermal element 79, a conductor bar being positioned below one leg of the bimetallic element, and an outlet conductor bar 81 being positioned below the other leg of said bimetallic element within said recess 77. A plurality of clamp screws 83 secure the terminals of the element 79 upon the conductor bars 80 and 81 and also within the base 15, the outlet bar 81 carrying a terminal screw 82 while the conductor bar 80 is further secured by a clamp screw 85 which engages a flexible conductor 84 adjacent one end, the other end of said conductor being secured upon the spring leaves 27 and 34. The tongue 78 is carried forward beneath the middle portion 96 of the thermal element 79, as at 97, to form a protective stop for excessive motion of said element, and a plurality of bosses 93 are provided on the base 15 to protect the terminal screws 82. Screw holes 94 are provided in the base 15, outside of the cover 16, to mount the device, after assembly, within a panel box or other desired location.

Inoperation, the current enters through the conductor 19, and, with the switch in closed po sition, passes through the buttons 36 and fingers 3.4 to the flexible conductor 84 and conductor 80 to the thermal element79 and out through 'the conductor 81. When the switch is being operated manually a movement of the knob 58 carries the upper end of spring 62 over the center of the toggle link 42 causing a flexing of the joint 45 and a consequent arcuate elevation of the frame 26 and spring leaves 27, 33 and 34. The leaves 27 and 33, being more flexed than leaf 34, tend to straighten as the pressure of the toggle is released, causing leaf 34 and buttons 36 to be elevated from the contact wing 22, as shown in Figure 7, while the carbon contacts are still maintained in full surface contact, thus breaking the main contacts without producing an arcing tendency of the current at this point. The loose rivets 28 and the pressure of leaf 33 insure a broad, fiat contact of the carbon surfaces to give good conductivity and to absorb the arc during the opening process. On closing the switch, the arcuate movement of the handle 55 tensions the main spring 62 against the link 42 and causes an arcuate swing of the link 42 about the pivot point 52 to straighten the toggle links and close the contacts. The arcuate motion is interrupted by the link 42 contacting with the stops 51 on the frame 47 before the pivotal points 52, 45 and 91 have come into alignment, the action of spring 62 on the offset extended portion 44 of the link 42 securing the toggle links from undue flexure from this partially aligned position until acted upon by a reaction of handle 55 or a movement of frame 47. By this construction a heavy pressure and rigid support for the spring leaves and contacts is induced, while a very slight motion' of either the handle 55 or frame 47 will produce an almost instantaneous and powerful breaking of the toggle support and opening of said contacts.

When operating as an overload circuit breaker,

an excess of current through the thermal element 79 produces a downward flexure of said element causing the catch 87 to release the leg 66 of the trip 63 when the upward pressure of pin 54 on the heel 71 produces a slight arcuate rotation of said trip to release the pin 54 and allow a limited upward swing of frame 47 under action of spring 62. As this frame starts in rotation, the extensions 51 produce an instantaneous breaking of the toggle joint 45 combined with a recessional movement of pivotal point 52 which collapses the toggle instantaneously with a correspondingly rapid opening of the contact buttons and carbon contacts. By adjustment of bracket 72, by means of screw 76, the amount of contact on strike 67 on the catch 87 may be calibrated, and the screw may then be mutilated so as to be further inoperative, rendering it impossible to alter the calibration of the device. In case the main spring 62 of the device becomes inoperative for any reason, a supplementary spring 37 is provided on the shaft 25 so tensioned as to open the contact points fully and automatically, and render the device inoperative until said main spring is repaired. As the opening action under overload conditions nears completion, spring 62 draws the handle 55 backward until the wings 61 contact with the legs 49 of frame 47 when the further movement of said handle under the combined action of the springs forces a rotative motion of frame 47 until the pin 54 engages the offset portion 70 of slot 69 and resets the strike 67 in engagement with the catch 8'1 on the thermal element 79. It is then necessary only to manually close the switch contacts by a single movement of the knob 58.

Having thus described my invention, what I claim as new is:-

' 1. In an automatic circuit breaker having an insulating base, a thermal element positioned wholly within and protected by said base, said element having each terminal thereof secured in series with an electric conductor wholly within and protected by the base member of said breaker, a housing member secured upon said base to essentially cover and protect said thermal element and render it essentially inaccessible from without said base, said thermal element having a metallic catch entirely surrounding the middle portion thereof but entirely insulated therefrom, the free portion of said thermal element being prevented from excessive flexing movement by said base and said housing and a cam controlled trip lever adjustably supported within said housing to releasably engage said thermal element in calibrated relation therewith.

2. In an electric switch and circuit breaker, a bifurcated yoke of U shape, a plurality of notched wings at the extremities of said yoke, a plurality of pivot seats in the side members of said U shape yoke in spaced relation with said notched wings-thereon, said side bars extending beyond said pivot seats and joined by an integral formed cross bar, said cross bar being out of alignment of a plane passing through said pivot seats and said notched wings, said yoke forming one link of a toggle, said crossbar engaging one end ofan overcenter spring for the operation of said circuit breaker.

3. In an electric switch and circuit breaker having an essentially U shaped frame mounted upon an insulating base, a swinging frame having essentially parallel side bars with an integrally formed cross member binding said side bars in spaced relation, a trip engaging pin secured in the opposite ends of said side bars from said cross member,. link engaging extensions integrally formed on said cross member in spaced relation with said side bars, said side bar's being provided with essentially rectangular aligned hinge seats to engage a swinging multiple link toggle for the operation of said switch, said extensions forcing the collapse of said toggle when said swinging frame is released, said swinging frame being pivotally mounted within said U shaped frame.

4. In a combined switch and circuit breaker having a housing with essentially parallel side members, a manually operable bifurcated handle having an insulation knob fixedly attached there on, said bifurcations being pivotally mounted upon said housing, a plurality of inwardly projecting wings integrally formed on the furcations of said handle, said wings engaging said side members to form a stop motion for said handle at one extremity of its oscillation and engaging a pair of spacedbars on a movable member mounted upon said housing said bars forming a stop motion for said handle at the opposite extremity of its oscillation.

5. An electric circuit breaker having a single helical spring of substantial proportions suspended pivotally between the side bars of an oscillating manual handle at one end of said spring, the opposite end of said spring engaging the cross bar of a U-shaped yoke hingedly supported by winged brackets adjacent the ends thereof in engagement with shoulders formed on side bars of a swinging frame pivotally mounted upon a housing, linkage members pivotally engaging said yoke between said cross bar and said winged brackets, a swinging bracket supported in said housing and engaging said linkage members, flexible contact carrying leaves attached fixedly to said bracket, said bracket, linkage members and yoke forming a toggle to actuate said flexible contact leaves, trip actuated means to release said swinging frame, fingers integral with said swinging frame to contact with said toggle adjacent its knee joint, said fingers mechanically moving said toggle and said spring, on overload release of said trip, to open said contacts with a snap action, wings on said oscillating handle co-operating with said fingers to compel said helical spring to rotate said swinging frame to a limit in one direction and subsequently to rotate said frame in the opposite direction to its initial position.

6. An electric circuit breaker having a main operating spring, a manually operable handle and an operating toggle linkage to open and close a plurality of circuit breaking contacts. a supplementary coil spring directly embodied in said linkage to automatically and independently open said circuit breaking contacts if said main spring becomes inoperative, and to render said device inoperative until said main spring shall again become operative. A

7. An electric circuit breaker having a main operating spring engaging an operating handle and a toggle linkage to open and close current carrying contacts connected with said toggle linkage, and an auxiliary coil spring associated with said toggle mechanism to open said current carrying contacts, either spring opening said contacts independenly of the other, said auxiliary spring automatically opening said contacts if the main spring becomes inoperative, and rendering said device further inoperative until said main spring shall have been restored to operative con dition.

8. A circuit breaker having an operating handle pivoted on a housing frame, a swinging sup port pivoted to said housing frame adjacent said handle, link engaging angles formed in side bars integral with said swinging support, a toggle linkage engaging said angles, forwardly projecting stops integral with said swinging support to engage and to limit the motion of said toggle linkage, said stops preventing said toggle links from ever assuming a rectilinear position, said stops moving arcuately with said swinging support to instantly flex the toggle linkage joint adjacent said stops and cause the collapse of said toggle when said swinging support is released for arcuate rotation, and an actuating spring connected with said handle for actuating said swinging frame and collapsing said toggle linkage.

9. In a circuit breaker having a housing and an oscillating handle pivoted thereto, a rotative frame mounted on said housing, a toggle linkage pivotally engaging said rotative frame, an oscillating current carrying arm pivotally connected to said toggle linkage, stops formed upon said rotative frame to engage said toggle linkage adjacent its central pivot, when said circuit breaker is in operative position, said stops preventing said pivotal points of said toggle linkage from assuming a rectilinear alignment at any position of its operation.

10. A circuit breaker having a housing and an oscillating handle pivoted thereto, an operating spring pivotally secured to said handle, an amuately movable frame secured to to said housing adjacent said handle, a U-shaped yoke pivotally engaging said frame, said spring being secured to the bottom portion of said u-shaped yoke, side links pivoted to said yokebetween said bottom portion and said frame pivot points, arcuately movable contact arms pivotally secured to said side links, said side links and said yoke forming a toggle between said arcuately movable frame and said contact arms, stops formed on said arcuately movable frame to engage said toggle adjacent its middle joint and to prevent said toggle pivot points from assuming a straight line position, the central plane of said spring when in operative position being within the angle formed by the pivot points of said toggle linkage.

11. A circuit breaker having a main operating spring, an operating handle, an oscillating con-' tact arm mounted in a housing for said breaker, a frame with plural side members secured upon said housing, a toggle yoke supported by said frame, toggle links pivotally connected to said contact arms, and said yoke in spaced relation to the supporting points of said yoke on said frame, said yoke extending beyond said link pivot points and having a cross bar at this extended end to which is attached the outer end of said operating spring, said cross bar approaching said contact arms when said circuit breaker is in closed position, said extension on said yoke and said cross bar maintaining said spring attachment point at an appreciable distance from the knee joint of said toggle links and said yoke to facilitate the action of said toggle construction.

12. In a circuit breaker having an insulating base and a housing thereon, a thermal element and conductors positioned in said base, an insulated catch on said thermal element, a trip pivoted in said housing in spaced relation with said catch, said trip releasably engaging said catch, a supplementary wing on said trip away from said catch engaging portion, said wing having a slot inclined toward said pivot point, an offset extremity in said slot adjacent said pivot, said offset portion forming a heel adjacent said pivot of said trip to engage a pin carried by a swinging frame pivotally supported by said housing, said pin being constrained within the offset portion of said slot while said trip is in operative engagement with said catch, but free to move arcuately within the limits of said slot when said trip is released from said catch, said slot coacting with said pin to maintain said trip out of engagement with said catch except when said pin is within the offset portion of said slot, said pin and slot also limiting the arcuate rotation of said swinging frame and maintaining said frame in latched position when said trip is in engagement with said catch on said thermal element.

13. In a circuit breaker having an operating spring, an oscillating handle and a housing, a swinging frame rotatively-mounted in said housing, a toggle engaging said swinging frame, a pin secured in the ends of said swinging frame, a yoke secured in adjusted position, a trip mounted in said yoke, and having a depending leg to engage a catch on a thermal element within the base of said circuit breaker, an upwardly projecting wing on said trip having a slot with an offset extremity adjacent the pivot point of said trip, an abutment formed by said slot and said offset portion, and being secured within said slot, said pin forcing said trip into engagement with said catch when in said offset portion, but restraining said trip from such engagement when within the main portion of said slot, said yoke regulating the amount of engagement of said trip with said catch and providing means for calibrationof said breaker and maintaining it in calibrated position.

14. In an electric circuit breaker having a housing with a swinging frame pivotally mounted thereon, an operating handle engaging said housing, an insulating knob upon the free end of said handle, spring operated means for actuating said handle and said swinging frame, a bimetallic element in electric series with said circuit breaker circuit and having an insulated catch thereon, a trip member normally engaging said catch and retaining said swinging frame in adjusted position, a projection integral with said trip member and having a formed slot therein, said slot engaging said swinging frame and limiting the arcuate movement thereof when said trip is released from said catch, plural projections on said handle engaging said swinging frame with a sharp impact blow to start the return of said swinging frame to its normal position the inertia of said knob and said handle completing the re-engagement of said trip member with said insulated catch after being released therefrom by fiexure of said bimetallic element.

15. A circuit breaker having a flexing thermal element mounted wholly within the insulating base of said breaker, an insulated catch supported by said element, an oscillating trip with a depending leg normally engaging said catch, an adjustable yoke supporting said trip, in adjustable position for calibration of said breaker, means for securing said yoke in adjusted position, a projection on said trip in essential alignment with said depending leg, a slot formed in said projection terminating adjacent the pivot point of said trip, an arcuately movable frame supported upon said circuit breaker frame, said movable frame engaging said formed slot and being limited in its movement thereby, spring actuated means to normally stress said movable frame upwardly against the portion of said slot adjacent the pivot point of said trip to maintain said depending leg in engagement with said catch, said movable frame forming a leverage to reduce the pressure of said spring actuated means upon said slot, and said trip member forming a leverage to further reduce the pressure of said spring actuated means upon said insulated catch and said thermal element to permit relative freedom of flexing movement of said thermal element.

16. In a combined electric switch and circuit breaker having an arcuately movable operating handle mounted on a housing, an oscillating helical spring engaging said handle, a biased oscillating lever pivotally mounted adjacent said handle, a slotted member limiting the oscillation of the free end of said lever, a thermally controlled catch controlling the movement of said slotted member, a plurality of flexible contact carrying arms pivotally mounted within said housing, toggle links connecting said contact carrying arms and said oscillating lever, means connected with said oscillating lever to positively and mechanically flex the knee joint of said toggle links when said trip is released from said catch, means connected with said handle to automatically reset said trip in engagement with said catch after release therefrom, a singlemotion of said handle moving said flexible contact carrying arms from open circuit to closed circuit position whether operated as a. switch or as a circuit breaker, said thermally controlled elements being operable to open said circuit breaker contacts even when said handle is restrained from movement to its open circuit position, essentially as described.

17. A circuit breaker consisting essentially of a U-shaped housing pivotally carrying a manually operable handle and a thermally controlled bifurcated lever arm adjacent said handle, a toggle seat formed in said lever arm, plural contact carrying levers arcuately movable within said housing, a multiple link toggle engaging said toggle seat and said plural contact levers, a forwardly projecting stop on said lever arm to limit the movement in one direction of said toggle so the pivotal points of said toggle may never come into rectilinear position, an operating spring connecting said handle and said toggle, said spring normally maintaining said toggle in contact with said projecting stop when said handle is in closed circuit position, a flexing thermal element engaging a pressure reducing trip lever releasably restraining said lever arm and said projecting stops" from arcuate motion, said projecting stops positrically operated thermal element to function under overload conditions, an insulated catch mounted upon said element a pivotal pressure reducing trip releasably engaging said thermal element, said trip being adjustably mounted within the housing of said breaker to engage said catch in calibrated relation thereto, a movable overarm permanentb engaging said trip, current carrying contacts in series with said thermal element, pivoted' spring arms in series with said contacts, a

multiple link pivotal toggle connecting said spring arms to said overarm, means associated integrally with said overarm to positively and simultaneously actuate a collapsing movement of said toggle with movement of said overarm upon release of said trip from said thermal element, said toggle being collapsed and said contacts being opened before said handle is operated to open circuit position by said operating spring.

19. In an electric circuit breaker having means for automatic overload release, an insulating base for said breaker, a fixed contact embedded in said base, an arcuately movable flexible contact to register with said fixed contact, said fixed contact having a fixed non-metallic element and a fixed metallic contact face, said flexible contact having a movably supported non-metallic element and an independently flexible metallic contact, said non-metallic contacts being mutually engageable and said metallic contacts being mutually engageable, said non-metallic contacts being maintained in full closed position until said metallic contacts have opened to a relatively wide gap on the opening cycle of said breaker, and said non-metallic contacts being mutually re-engaged while said metallic contacts are still relatively far apart on the closing cycle of said circuit breaker,

said flexible contact having associated means to automatically disengage said contacts .upon the.

ently flexible copper contact associated therewith,

said carbons being mounted without thev use of screw threads, holes, plugs, or other means of internal attachment, said flexible arms being pro-' vided with means for independently opening said contacts in case of failure of the main operating elements of said breaker.

THEODORE A. SPERRY. 

